// SPDX-License-Identifier: GPL-2.0-or-later
/*
    file operation functions
    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
    Copyright (C) 2004  Chris Kennedy <c@groovy.org>
    Copyright (C) 2005-2007  Hans Verkuil <hverkuil@kernel.org>

 */

#include "ivtv-driver.h"
#include "ivtv-fileops.h"
#include "ivtv-i2c.h"
#include "ivtv-queue.h"
#include "ivtv-udma.h"
#include "ivtv-irq.h"
#include "ivtv-vbi.h"
#include "ivtv-mailbox.h"
#include "ivtv-routing.h"
#include "ivtv-streams.h"
#include "ivtv-yuv.h"
#include "ivtv-ioctl.h"
#include "ivtv-cards.h"
#include "ivtv-firmware.h"
#include <linux/lockdep.h>
#include <media/v4l2-event.h>
#include <media/i2c/saa7115.h>

/* This function tries to claim the stream for a specific file descriptor.
   If no one else is using this stream then the stream is claimed and
   associated VBI streams are also automatically claimed.
   Possible error returns: -EBUSY if someone else has claimed
   the stream or 0 on success. */
int ivtv_claim_stream(struct ivtv_open_id *id, int type)
{
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[type];
        struct ivtv_stream *s_vbi;
        int vbi_type;

        if (test_and_set_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
                /* someone already claimed this stream */
                if (s->id == id) {
                        /* yes, this file descriptor did. So that's OK. */
                        return 0;
                }
                if (s->id == NULL && (type == IVTV_DEC_STREAM_TYPE_VBI ||
                                         type == IVTV_ENC_STREAM_TYPE_VBI)) {
                        /* VBI is handled already internally, now also assign
                           the file descriptor to this stream for external
                           reading of the stream. */
                        s->id = id;
                        IVTV_DEBUG_INFO("Start Read VBI\n");
                        return 0;
                }
                /* someone else is using this stream already */
                IVTV_DEBUG_INFO("Stream %d is busy\n", type);
                return -EBUSY;
        }
        s->id = id;
        if (type == IVTV_DEC_STREAM_TYPE_VBI) {
                /* Enable reinsertion interrupt */
                ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
        }

        /* IVTV_DEC_STREAM_TYPE_MPG needs to claim IVTV_DEC_STREAM_TYPE_VBI,
           IVTV_ENC_STREAM_TYPE_MPG needs to claim IVTV_ENC_STREAM_TYPE_VBI
           (provided VBI insertion is on and sliced VBI is selected), for all
           other streams we're done */
        if (type == IVTV_DEC_STREAM_TYPE_MPG) {
                vbi_type = IVTV_DEC_STREAM_TYPE_VBI;
        } else if (type == IVTV_ENC_STREAM_TYPE_MPG &&
                   itv->vbi.insert_mpeg && !ivtv_raw_vbi(itv)) {
                vbi_type = IVTV_ENC_STREAM_TYPE_VBI;
        } else {
                return 0;
        }
        s_vbi = &itv->streams[vbi_type];

        if (!test_and_set_bit(IVTV_F_S_CLAIMED, &s_vbi->s_flags)) {
                /* Enable reinsertion interrupt */
                if (vbi_type == IVTV_DEC_STREAM_TYPE_VBI)
                        ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
        }
        /* mark that it is used internally */
        set_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags);
        return 0;
}
EXPORT_SYMBOL(ivtv_claim_stream);

/* This function releases a previously claimed stream. It will take into
   account associated VBI streams. */
void ivtv_release_stream(struct ivtv_stream *s)
{
        struct ivtv *itv = s->itv;
        struct ivtv_stream *s_vbi;

        s->id = NULL;
        if ((s->type == IVTV_DEC_STREAM_TYPE_VBI || s->type == IVTV_ENC_STREAM_TYPE_VBI) &&
                test_bit(IVTV_F_S_INTERNAL_USE, &s->s_flags)) {
                /* this stream is still in use internally */
                return;
        }
        if (!test_and_clear_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
                IVTV_DEBUG_WARN("Release stream %s not in use!\n", s->name);
                return;
        }

        ivtv_flush_queues(s);

        /* disable reinsertion interrupt */
        if (s->type == IVTV_DEC_STREAM_TYPE_VBI)
                ivtv_set_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);

        /* IVTV_DEC_STREAM_TYPE_MPG needs to release IVTV_DEC_STREAM_TYPE_VBI,
           IVTV_ENC_STREAM_TYPE_MPG needs to release IVTV_ENC_STREAM_TYPE_VBI,
           for all other streams we're done */
        if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
                s_vbi = &itv->streams[IVTV_DEC_STREAM_TYPE_VBI];
        else if (s->type == IVTV_ENC_STREAM_TYPE_MPG)
                s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
        else
                return;

        /* clear internal use flag */
        if (!test_and_clear_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags)) {
                /* was already cleared */
                return;
        }
        if (s_vbi->id) {
                /* VBI stream still claimed by a file descriptor */
                return;
        }
        /* disable reinsertion interrupt */
        if (s_vbi->type == IVTV_DEC_STREAM_TYPE_VBI)
                ivtv_set_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
        clear_bit(IVTV_F_S_CLAIMED, &s_vbi->s_flags);
        ivtv_flush_queues(s_vbi);
}
EXPORT_SYMBOL(ivtv_release_stream);

static void ivtv_dualwatch(struct ivtv *itv)
{
        struct v4l2_tuner vt;
        u32 new_stereo_mode;
        const u32 dual = 0x02;

        new_stereo_mode = v4l2_ctrl_g_ctrl(itv->cxhdl.audio_mode);
        memset(&vt, 0, sizeof(vt));
        ivtv_call_all(itv, tuner, g_tuner, &vt);
        if (vt.audmode == V4L2_TUNER_MODE_LANG1_LANG2 && (vt.rxsubchans & V4L2_TUNER_SUB_LANG2))
                new_stereo_mode = dual;

        if (new_stereo_mode == itv->dualwatch_stereo_mode)
                return;

        IVTV_DEBUG_INFO("dualwatch: change stereo flag from 0x%x to 0x%x.\n",
                           itv->dualwatch_stereo_mode, new_stereo_mode);
        if (v4l2_ctrl_s_ctrl(itv->cxhdl.audio_mode, new_stereo_mode))
                IVTV_DEBUG_INFO("dualwatch: changing stereo flag failed\n");
}

static void ivtv_update_pgm_info(struct ivtv *itv)
{
        u32 wr_idx = (read_enc(itv->pgm_info_offset) - itv->pgm_info_offset - 4) / 24;
        int cnt;
        int i = 0;

        if (wr_idx >= itv->pgm_info_num) {
                IVTV_DEBUG_WARN("Invalid PGM index %d (>= %d)\n", wr_idx, itv->pgm_info_num);
                return;
        }
        cnt = (wr_idx + itv->pgm_info_num - itv->pgm_info_write_idx) % itv->pgm_info_num;
        while (i < cnt) {
                int idx = (itv->pgm_info_write_idx + i) % itv->pgm_info_num;
                struct v4l2_enc_idx_entry *e = itv->pgm_info + idx;
                u32 addr = itv->pgm_info_offset + 4 + idx * 24;
                const int mapping[8] = { -1, V4L2_ENC_IDX_FRAME_I, V4L2_ENC_IDX_FRAME_P, -1,
                        V4L2_ENC_IDX_FRAME_B, -1, -1, -1 };
                                        // 1=I, 2=P, 4=B

                e->offset = read_enc(addr + 4) + ((u64)read_enc(addr + 8) << 32);
                if (e->offset > itv->mpg_data_received) {
                        break;
                }
                e->offset += itv->vbi_data_inserted;
                e->length = read_enc(addr);
                e->pts = read_enc(addr + 16) + ((u64)(read_enc(addr + 20) & 1) << 32);
                e->flags = mapping[read_enc(addr + 12) & 7];
                i++;
        }
        itv->pgm_info_write_idx = (itv->pgm_info_write_idx + i) % itv->pgm_info_num;
}

static void ivtv_schedule(struct ivtv_stream *s)
{
        struct ivtv *itv = s->itv;
        DEFINE_WAIT(wait);

        lockdep_assert_held(&itv->serialize_lock);

        mutex_unlock(&itv->serialize_lock);
        prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
        /* New buffers might have become free before we were added to the waitqueue */
        if (!s->q_free.buffers)
                schedule();
        finish_wait(&s->waitq, &wait);
        mutex_lock(&itv->serialize_lock);
}

static struct ivtv_buffer *ivtv_get_buffer(struct ivtv_stream *s, int non_block, int *err)
{
        struct ivtv *itv = s->itv;
        struct ivtv_stream *s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
        struct ivtv_buffer *buf;

        *err = 0;
        while (1) {
                if (s->type == IVTV_ENC_STREAM_TYPE_MPG) {
                        /* Process pending program info updates and pending VBI data */
                        ivtv_update_pgm_info(itv);

                        if (time_after(jiffies,
                                       itv->dualwatch_jiffies +
                                       msecs_to_jiffies(1000))) {
                                itv->dualwatch_jiffies = jiffies;
                                ivtv_dualwatch(itv);
                        }

                        if (test_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
                            !test_bit(IVTV_F_S_APPL_IO, &s_vbi->s_flags)) {
                                while ((buf = ivtv_dequeue(s_vbi, &s_vbi->q_full))) {
                                        /* byteswap and process VBI data */
                                        ivtv_process_vbi_data(itv, buf, s_vbi->dma_pts, s_vbi->type);
                                        ivtv_enqueue(s_vbi, buf, &s_vbi->q_free);
                                }
                        }
                        buf = &itv->vbi.sliced_mpeg_buf;
                        if (buf->readpos != buf->bytesused) {
                                return buf;
                        }
                }

                /* do we have leftover data? */
                buf = ivtv_dequeue(s, &s->q_io);
                if (buf)
                        return buf;

                /* do we have new data? */
                buf = ivtv_dequeue(s, &s->q_full);
                if (buf) {
                        if ((buf->b_flags & IVTV_F_B_NEED_BUF_SWAP) == 0)
                                return buf;
                        buf->b_flags &= ~IVTV_F_B_NEED_BUF_SWAP;
                        if (s->type == IVTV_ENC_STREAM_TYPE_MPG)
                                /* byteswap MPG data */
                                ivtv_buf_swap(buf);
                        else if (s->type != IVTV_DEC_STREAM_TYPE_VBI) {
                                /* byteswap and process VBI data */
                                ivtv_process_vbi_data(itv, buf, s->dma_pts, s->type);
                        }
                        return buf;
                }

                /* return if end of stream */
                if (s->type != IVTV_DEC_STREAM_TYPE_VBI && !test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
                        IVTV_DEBUG_INFO("EOS %s\n", s->name);
                        return NULL;
                }

                /* return if file was opened with O_NONBLOCK */
                if (non_block) {
                        *err = -EAGAIN;
                        return NULL;
                }

                /* wait for more data to arrive */
                ivtv_schedule(s);
                if (signal_pending(current)) {
                        /* return if a signal was received */
                        IVTV_DEBUG_INFO("User stopped %s\n", s->name);
                        *err = -EINTR;
                        return NULL;
                }
        }
}

static void ivtv_setup_sliced_vbi_buf(struct ivtv *itv)
{
        int idx = itv->vbi.inserted_frame % IVTV_VBI_FRAMES;

        itv->vbi.sliced_mpeg_buf.buf = itv->vbi.sliced_mpeg_data[idx];
        itv->vbi.sliced_mpeg_buf.bytesused = itv->vbi.sliced_mpeg_size[idx];
        itv->vbi.sliced_mpeg_buf.readpos = 0;
}

static size_t ivtv_copy_buf_to_user(struct ivtv_stream *s, struct ivtv_buffer *buf,
                char __user *ubuf, size_t ucount)
{
        struct ivtv *itv = s->itv;
        size_t len = buf->bytesused - buf->readpos;

        if (len > ucount) len = ucount;
        if (itv->vbi.insert_mpeg && s->type == IVTV_ENC_STREAM_TYPE_MPG &&
            !ivtv_raw_vbi(itv) && buf != &itv->vbi.sliced_mpeg_buf) {
                const char *start = buf->buf + buf->readpos;
                const char *p = start + 1;
                const u8 *q;
                u8 ch = itv->search_pack_header ? 0xba : 0xe0;
                int stuffing, i;

                while (start + len > p && (q = memchr(p, 0, start + len - p))) {
                        p = q + 1;
                        if ((char *)q + 15 >= buf->buf + buf->bytesused ||
                            q[1] != 0 || q[2] != 1 || q[3] != ch) {
                                continue;
                        }
                        if (!itv->search_pack_header) {
                                if ((q[6] & 0xc0) != 0x80)
                                        continue;
                                if (((q[7] & 0xc0) == 0x80 && (q[9] & 0xf0) == 0x20) ||
                                    ((q[7] & 0xc0) == 0xc0 && (q[9] & 0xf0) == 0x30)) {
                                        ch = 0xba;
                                        itv->search_pack_header = 1;
                                        p = q + 9;
                                }
                                continue;
                        }
                        stuffing = q[13] & 7;
                        /* all stuffing bytes must be 0xff */
                        for (i = 0; i < stuffing; i++)
                                if (q[14 + i] != 0xff)
                                        break;
                        if (i == stuffing && (q[4] & 0xc4) == 0x44 && (q[12] & 3) == 3 &&
                                        q[14 + stuffing] == 0 && q[15 + stuffing] == 0 &&
                                        q[16 + stuffing] == 1) {
                                itv->search_pack_header = 0;
                                len = (char *)q - start;
                                ivtv_setup_sliced_vbi_buf(itv);
                                break;
                        }
                }
        }
        if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
                IVTV_DEBUG_WARN("copy %zd bytes to user failed for %s\n", len, s->name);
                return -EFAULT;
        }
        /*IVTV_INFO("copied %lld %d %d %d %d %d vbi %d\n", itv->mpg_data_received, len, ucount,
                        buf->readpos, buf->bytesused, buf->bytesused - buf->readpos - len,
                        buf == &itv->vbi.sliced_mpeg_buf); */
        buf->readpos += len;
        if (s->type == IVTV_ENC_STREAM_TYPE_MPG && buf != &itv->vbi.sliced_mpeg_buf)
                itv->mpg_data_received += len;
        return len;
}

static ssize_t ivtv_read(struct ivtv_stream *s, char __user *ubuf, size_t tot_count, int non_block)
{
        struct ivtv *itv = s->itv;
        size_t tot_written = 0;
        int single_frame = 0;

        if (atomic_read(&itv->capturing) == 0 && s->id == NULL) {
                /* shouldn't happen */
                IVTV_DEBUG_WARN("Stream %s not initialized before read\n", s->name);
                return -EIO;
        }

        /* Each VBI buffer is one frame, the v4l2 API says that for VBI the frames should
           arrive one-by-one, so make sure we never output more than one VBI frame at a time */
        if (s->type == IVTV_DEC_STREAM_TYPE_VBI ||
            (s->type == IVTV_ENC_STREAM_TYPE_VBI && !ivtv_raw_vbi(itv)))
                single_frame = 1;

        for (;;) {
                struct ivtv_buffer *buf;
                int rc;

                buf = ivtv_get_buffer(s, non_block, &rc);
                /* if there is no data available... */
                if (buf == NULL) {
                        /* if we got data, then return that regardless */
                        if (tot_written)
                                break;
                        /* EOS condition */
                        if (rc == 0) {
                                clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
                                clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                                ivtv_release_stream(s);
                        }
                        /* set errno */
                        return rc;
                }
                rc = ivtv_copy_buf_to_user(s, buf, ubuf + tot_written, tot_count - tot_written);
                if (buf != &itv->vbi.sliced_mpeg_buf) {
                        ivtv_enqueue(s, buf, (buf->readpos == buf->bytesused) ? &s->q_free : &s->q_io);
                }
                else if (buf->readpos == buf->bytesused) {
                        int idx = itv->vbi.inserted_frame % IVTV_VBI_FRAMES;
                        itv->vbi.sliced_mpeg_size[idx] = 0;
                        itv->vbi.inserted_frame++;
                        itv->vbi_data_inserted += buf->bytesused;
                }
                if (rc < 0)
                        return rc;
                tot_written += rc;

                if (tot_written == tot_count || single_frame)
                        break;
        }
        return tot_written;
}

static ssize_t ivtv_read_pos(struct ivtv_stream *s, char __user *ubuf, size_t count,
                        loff_t *pos, int non_block)
{
        ssize_t rc = count ? ivtv_read(s, ubuf, count, non_block) : 0;
        struct ivtv *itv = s->itv;

        IVTV_DEBUG_HI_FILE("read %zd from %s, got %zd\n", count, s->name, rc);
        if (rc > 0)
                *pos += rc;
        return rc;
}

int ivtv_start_capture(struct ivtv_open_id *id)
{
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        struct ivtv_stream *s_vbi;

        if (s->type == IVTV_ENC_STREAM_TYPE_RAD ||
            s->type == IVTV_DEC_STREAM_TYPE_MPG ||
            s->type == IVTV_DEC_STREAM_TYPE_YUV ||
            s->type == IVTV_DEC_STREAM_TYPE_VOUT) {
                /* you cannot read from these stream types. */
                return -EINVAL;
        }

        /* Try to claim this stream. */
        if (ivtv_claim_stream(id, s->type))
                return -EBUSY;

        /* This stream does not need to start capturing */
        if (s->type == IVTV_DEC_STREAM_TYPE_VBI) {
                set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                return 0;
        }

        /* If capture is already in progress, then we also have to
           do nothing extra. */
        if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) || test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
                set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                return 0;
        }

        /* Start VBI capture if required */
        s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
        if (s->type == IVTV_ENC_STREAM_TYPE_MPG &&
            test_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
            !test_and_set_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags)) {
                /* Note: the IVTV_ENC_STREAM_TYPE_VBI is claimed
                   automatically when the MPG stream is claimed.
                   We only need to start the VBI capturing. */
                if (ivtv_start_v4l2_encode_stream(s_vbi)) {
                        IVTV_DEBUG_WARN("VBI capture start failed\n");

                        /* Failure, clean up and return an error */
                        clear_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags);
                        clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
                        /* also releases the associated VBI stream */
                        ivtv_release_stream(s);
                        return -EIO;
                }
                IVTV_DEBUG_INFO("VBI insertion started\n");
        }

        /* Tell the card to start capturing */
        if (!ivtv_start_v4l2_encode_stream(s)) {
                /* We're done */
                set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                /* Resume a possibly paused encoder */
                if (test_and_clear_bit(IVTV_F_I_ENC_PAUSED, &itv->i_flags))
                        ivtv_vapi(itv, CX2341X_ENC_PAUSE_ENCODER, 1, 1);
                return 0;
        }

        /* failure, clean up */
        IVTV_DEBUG_WARN("Failed to start capturing for stream %s\n", s->name);

        /* Note: the IVTV_ENC_STREAM_TYPE_VBI is released
           automatically when the MPG stream is released.
           We only need to stop the VBI capturing. */
        if (s->type == IVTV_ENC_STREAM_TYPE_MPG &&
            test_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags)) {
                ivtv_stop_v4l2_encode_stream(s_vbi, 0);
                clear_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags);
        }
        clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
        ivtv_release_stream(s);
        return -EIO;
}

ssize_t ivtv_v4l2_read(struct file * filp, char __user *buf, size_t count, loff_t * pos)
{
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        ssize_t rc;

        IVTV_DEBUG_HI_FILE("read %zd bytes from %s\n", count, s->name);

        if (mutex_lock_interruptible(&itv->serialize_lock))
                return -ERESTARTSYS;
        rc = ivtv_start_capture(id);
        if (!rc)
                rc = ivtv_read_pos(s, buf, count, pos, filp->f_flags & O_NONBLOCK);
        mutex_unlock(&itv->serialize_lock);
        return rc;
}

int ivtv_start_decoding(struct ivtv_open_id *id, int speed)
{
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        int rc;

        if (atomic_read(&itv->decoding) == 0) {
                if (ivtv_claim_stream(id, s->type)) {
                        /* someone else is using this stream already */
                        IVTV_DEBUG_WARN("start decode, stream already claimed\n");
                        return -EBUSY;
                }
                rc = ivtv_start_v4l2_decode_stream(s, 0);
                if (rc < 0) {
                        if (rc == -EAGAIN)
                                rc = ivtv_start_v4l2_decode_stream(s, 0);
                        if (rc < 0)
                                return rc;
                }
        }
        if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
                return ivtv_set_speed(itv, speed);
        return 0;
}

static int ivtv_schedule_dma(struct ivtv_stream *s)
{
        struct ivtv *itv = s->itv;
        int got_sig;
        DEFINE_WAIT(wait);

        lockdep_assert_held(&itv->serialize_lock);

        mutex_unlock(&itv->serialize_lock);
        prepare_to_wait(&itv->dma_waitq, &wait, TASK_INTERRUPTIBLE);
        while (!(got_sig = signal_pending(current)) &&
               test_bit(IVTV_F_S_DMA_PENDING, &s->s_flags))
                schedule();
        finish_wait(&itv->dma_waitq, &wait);
        mutex_lock(&itv->serialize_lock);

        return got_sig;
}

static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *pos)
{
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        struct yuv_playback_info *yi = &itv->yuv_info;
        struct ivtv_buffer *buf;
        struct ivtv_queue q;
        int bytes_written = 0;
        int mode;
        int rc;

        IVTV_DEBUG_HI_FILE("write %zd bytes to %s\n", count, s->name);

        if (s->type != IVTV_DEC_STREAM_TYPE_MPG &&
            s->type != IVTV_DEC_STREAM_TYPE_YUV &&
            s->type != IVTV_DEC_STREAM_TYPE_VOUT)
                /* not decoder streams */
                return -EINVAL;

        /* Try to claim this stream */
        if (ivtv_claim_stream(id, s->type))
                return -EBUSY;

        /* This stream does not need to start any decoding */
        if (s->type == IVTV_DEC_STREAM_TYPE_VOUT) {
                int elems = count / sizeof(struct v4l2_sliced_vbi_data);

                set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                return ivtv_write_vbi_from_user(itv,
                   (const struct v4l2_sliced_vbi_data __user *)user_buf, elems);
        }

        mode = s->type == IVTV_DEC_STREAM_TYPE_MPG ? OUT_MPG : OUT_YUV;

        if (ivtv_set_output_mode(itv, mode) != mode) {
            ivtv_release_stream(s);
            return -EBUSY;
        }
        ivtv_queue_init(&q);
        set_bit(IVTV_F_S_APPL_IO, &s->s_flags);

        /* Start decoder (returns 0 if already started) */
        rc = ivtv_start_decoding(id, itv->speed);
        if (rc) {
                IVTV_DEBUG_WARN("Failed start decode stream %s\n", s->name);

                /* failure, clean up */
                clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
                clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                return rc;
        }

retry:
        /* If possible, just DMA the entire frame - Check the data transfer size
        since we may get here before the stream has been fully set-up */
        if (mode == OUT_YUV && s->q_full.length == 0 && itv->dma_data_req_size) {
                while (count >= itv->dma_data_req_size) {
                        rc = ivtv_yuv_udma_stream_frame(itv, (void __user *)user_buf);

                        if (rc < 0)
                                return rc;

                        bytes_written += itv->dma_data_req_size;
                        user_buf += itv->dma_data_req_size;
                        count -= itv->dma_data_req_size;
                }
                if (count == 0) {
                        IVTV_DEBUG_HI_FILE("Wrote %d bytes to %s (%d)\n", bytes_written, s->name, s->q_full.bytesused);
                        return bytes_written;
                }
        }

        for (;;) {
                /* Gather buffers */
                while (q.length - q.bytesused < count && (buf = ivtv_dequeue(s, &s->q_io)))
                        ivtv_enqueue(s, buf, &q);
                while (q.length - q.bytesused < count && (buf = ivtv_dequeue(s, &s->q_free))) {
                        ivtv_enqueue(s, buf, &q);
                }
                if (q.buffers)
                        break;
                if (filp->f_flags & O_NONBLOCK)
                        return -EAGAIN;
                ivtv_schedule(s);
                if (signal_pending(current)) {
                        IVTV_DEBUG_INFO("User stopped %s\n", s->name);
                        return -EINTR;
                }
        }

        /* copy user data into buffers */
        while ((buf = ivtv_dequeue(s, &q))) {
                /* yuv is a pain. Don't copy more data than needed for a single
                   frame, otherwise we lose sync with the incoming stream */
                if (s->type == IVTV_DEC_STREAM_TYPE_YUV &&
                    yi->stream_size + count > itv->dma_data_req_size)
                        rc  = ivtv_buf_copy_from_user(s, buf, user_buf,
                                itv->dma_data_req_size - yi->stream_size);
                else
                        rc = ivtv_buf_copy_from_user(s, buf, user_buf, count);

                /* Make sure we really got all the user data */
                if (rc < 0) {
                        ivtv_queue_move(s, &q, NULL, &s->q_free, 0);
                        return rc;
                }
                user_buf += rc;
                count -= rc;
                bytes_written += rc;

                if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
                        yi->stream_size += rc;
                        /* If we have a complete yuv frame, break loop now */
                        if (yi->stream_size == itv->dma_data_req_size) {
                                ivtv_enqueue(s, buf, &s->q_full);
                                yi->stream_size = 0;
                                break;
                        }
                }

                if (buf->bytesused != s->buf_size) {
                        /* incomplete, leave in q_io for next time */
                        ivtv_enqueue(s, buf, &s->q_io);
                        break;
                }
                /* Byteswap MPEG buffer */
                if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
                        ivtv_buf_swap(buf);
                ivtv_enqueue(s, buf, &s->q_full);
        }

        if (test_bit(IVTV_F_S_NEEDS_DATA, &s->s_flags)) {
                if (s->q_full.length >= itv->dma_data_req_size) {
                        if (mode == OUT_YUV)
                                ivtv_yuv_setup_stream_frame(itv);

                        if (ivtv_schedule_dma(s)) {
                                IVTV_DEBUG_INFO("User interrupted %s\n", s->name);
                                return -EINTR;
                        }

                        clear_bit(IVTV_F_S_NEEDS_DATA, &s->s_flags);
                        ivtv_queue_move(s, &s->q_full, NULL, &s->q_predma, itv->dma_data_req_size);
                        ivtv_dma_stream_dec_prepare(s, itv->dma_data_req_offset + IVTV_DECODER_OFFSET, 1);
                }
        }
        /* more user data is available, wait until buffers become free
           to transfer the rest. */
        if (count && !(filp->f_flags & O_NONBLOCK))
                goto retry;
        IVTV_DEBUG_HI_FILE("Wrote %d bytes to %s (%d)\n", bytes_written, s->name, s->q_full.bytesused);
        return bytes_written;
}

ssize_t ivtv_v4l2_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *pos)
{
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        ssize_t res;

        if (mutex_lock_interruptible(&itv->serialize_lock))
                return -ERESTARTSYS;
        res = ivtv_write(filp, user_buf, count, pos);
        mutex_unlock(&itv->serialize_lock);
        return res;
}

__poll_t ivtv_v4l2_dec_poll(struct file *filp, poll_table *wait)
{
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        __poll_t res = 0;

        /* add stream's waitq to the poll list */
        IVTV_DEBUG_HI_FILE("Decoder poll\n");

        /* If there are subscribed events, then only use the new event
           API instead of the old video.h based API. */
        if (!list_empty(&id->fh.subscribed)) {
                poll_wait(filp, &id->fh.wait, wait);
                /* Turn off the old-style vsync events */
                clear_bit(IVTV_F_I_EV_VSYNC_ENABLED, &itv->i_flags);
                if (v4l2_event_pending(&id->fh))
                        res = EPOLLPRI;
        } else {
                /* This is the old-style API which is here only for backwards
                   compatibility. */
                poll_wait(filp, &s->waitq, wait);
                set_bit(IVTV_F_I_EV_VSYNC_ENABLED, &itv->i_flags);
                if (test_bit(IVTV_F_I_EV_VSYNC, &itv->i_flags) ||
                    test_bit(IVTV_F_I_EV_DEC_STOPPED, &itv->i_flags))
                        res = EPOLLPRI;
        }

        /* Allow write if buffers are available for writing */
        if (s->q_free.buffers)
                res |= EPOLLOUT | EPOLLWRNORM;
        return res;
}

__poll_t ivtv_v4l2_enc_poll(struct file *filp, poll_table *wait)
{
        __poll_t req_events = poll_requested_events(wait);
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];
        int eof = test_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
        __poll_t res = 0;

        /* Start a capture if there is none */
        if (!eof && !test_bit(IVTV_F_S_STREAMING, &s->s_flags) &&
                        s->type != IVTV_ENC_STREAM_TYPE_RAD &&
                        (req_events & (EPOLLIN | EPOLLRDNORM))) {
                int rc;

                mutex_lock(&itv->serialize_lock);
                rc = ivtv_start_capture(id);
                mutex_unlock(&itv->serialize_lock);
                if (rc) {
                        IVTV_DEBUG_INFO("Could not start capture for %s (%d)\n",
                                        s->name, rc);
                        return EPOLLERR;
                }
                IVTV_DEBUG_FILE("Encoder poll started capture\n");
        }

        /* add stream's waitq to the poll list */
        IVTV_DEBUG_HI_FILE("Encoder poll\n");
        poll_wait(filp, &s->waitq, wait);
        if (v4l2_event_pending(&id->fh))
                res |= EPOLLPRI;
        else
                poll_wait(filp, &id->fh.wait, wait);

        if (s->q_full.length || s->q_io.length)
                return res | EPOLLIN | EPOLLRDNORM;
        if (eof)
                return res | EPOLLHUP;
        return res;
}

void ivtv_stop_capture(struct ivtv_open_id *id, int gop_end)
{
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];

        IVTV_DEBUG_FILE("close() of %s\n", s->name);

        /* 'Unclaim' this stream */

        /* Stop capturing */
        if (test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
                struct ivtv_stream *s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];

                IVTV_DEBUG_INFO("close stopping capture\n");
                /* Special case: a running VBI capture for VBI insertion
                   in the mpeg stream. Need to stop that too. */
                if (id->type == IVTV_ENC_STREAM_TYPE_MPG &&
                    test_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags) &&
                    !test_bit(IVTV_F_S_APPL_IO, &s_vbi->s_flags)) {
                        IVTV_DEBUG_INFO("close stopping embedded VBI capture\n");
                        ivtv_stop_v4l2_encode_stream(s_vbi, 0);
                }
                if ((id->type == IVTV_DEC_STREAM_TYPE_VBI ||
                     id->type == IVTV_ENC_STREAM_TYPE_VBI) &&
                    test_bit(IVTV_F_S_INTERNAL_USE, &s->s_flags)) {
                        /* Also used internally, don't stop capturing */
                        s->id = NULL;
                }
                else {
                        ivtv_stop_v4l2_encode_stream(s, gop_end);
                }
        }
        if (!gop_end) {
                clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
                ivtv_release_stream(s);
        }
}

static void ivtv_stop_decoding(struct ivtv_open_id *id, int flags, u64 pts)
{
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];

        IVTV_DEBUG_FILE("close() of %s\n", s->name);

        if (id->type == IVTV_DEC_STREAM_TYPE_YUV &&
                test_bit(IVTV_F_I_DECODING_YUV, &itv->i_flags)) {
                /* Restore registers we've changed & clean up any mess */
                ivtv_yuv_close(itv);
        }

        /* Stop decoding */
        if (test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
                IVTV_DEBUG_INFO("close stopping decode\n");

                ivtv_stop_v4l2_decode_stream(s, flags, pts);
                itv->output_mode = OUT_NONE;
        }
        clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);

        if (itv->output_mode == OUT_UDMA_YUV && id->yuv_frames)
                itv->output_mode = OUT_NONE;

        itv->speed = 0;
        clear_bit(IVTV_F_I_DEC_PAUSED, &itv->i_flags);
        ivtv_release_stream(s);
}

int ivtv_v4l2_close(struct file *filp)
{
        struct v4l2_fh *fh = file_to_v4l2_fh(filp);
        struct ivtv_open_id *id = file2id(filp);
        struct ivtv *itv = id->itv;
        struct ivtv_stream *s = &itv->streams[id->type];

        IVTV_DEBUG_FILE("close %s\n", s->name);

        mutex_lock(&itv->serialize_lock);

        /* Stop radio */
        if (id->type == IVTV_ENC_STREAM_TYPE_RAD &&
                        v4l2_fh_is_singular_file(filp)) {
                /* Closing radio device, return to TV mode */
                ivtv_mute(itv);
                /* Mark that the radio is no longer in use */
                clear_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
                /* Switch tuner to TV */
                ivtv_call_all(itv, video, s_std, itv->std);
                /* Select correct audio input (i.e. TV tuner or Line in) */
                ivtv_audio_set_io(itv);
                if (itv->hw_flags & IVTV_HW_SAA711X) {
                        ivtv_call_hw(itv, IVTV_HW_SAA711X, video, s_crystal_freq,
                                        SAA7115_FREQ_32_11_MHZ, 0);
                }
                if (atomic_read(&itv->capturing) > 0) {
                        /* Undo video mute */
                        ivtv_vapi(itv, CX2341X_ENC_MUTE_VIDEO, 1,
                                        v4l2_ctrl_g_ctrl(itv->cxhdl.video_mute) |
                                        (v4l2_ctrl_g_ctrl(itv->cxhdl.video_mute_yuv) << 8));
                }
                /* Done! Unmute and continue. */
                ivtv_unmute(itv);
        }

        v4l2_fh_del(fh, filp);
        v4l2_fh_exit(fh);

        /* Easy case first: this stream was never claimed by us */
        if (s->id != id)
                goto close_done;

        /* 'Unclaim' this stream */

        if (s->type >= IVTV_DEC_STREAM_TYPE_MPG) {
                struct ivtv_stream *s_vout = &itv->streams[IVTV_DEC_STREAM_TYPE_VOUT];

                ivtv_stop_decoding(id, V4L2_DEC_CMD_STOP_TO_BLACK | V4L2_DEC_CMD_STOP_IMMEDIATELY, 0);

                /* If all output streams are closed, and if the user doesn't have
                   IVTV_DEC_STREAM_TYPE_VOUT open, then disable CC on TV-out. */
                if (itv->output_mode == OUT_NONE && !test_bit(IVTV_F_S_APPL_IO, &s_vout->s_flags)) {
                        /* disable CC on TV-out */
                        ivtv_disable_cc(itv);
                }
        } else {
                ivtv_stop_capture(id, 0);
        }
close_done:
        kfree(id);
        mutex_unlock(&itv->serialize_lock);
        return 0;
}

static int ivtv_open(struct file *filp)
{
        struct video_device *vdev = video_devdata(filp);
        struct ivtv_stream *s = video_get_drvdata(vdev);
        struct ivtv *itv = s->itv;
        struct ivtv_open_id *item;
        int res = 0;

        IVTV_DEBUG_FILE("open %s\n", s->name);

        if (ivtv_init_on_first_open(itv)) {
                IVTV_ERR("Failed to initialize on device %s\n",
                         video_device_node_name(vdev));
                return -ENXIO;
        }

#ifdef CONFIG_VIDEO_ADV_DEBUG
        /* Unless ivtv_fw_debug is set, error out if firmware dead. */
        if (ivtv_fw_debug) {
                IVTV_WARN("Opening %s with dead firmware lockout disabled\n",
                          video_device_node_name(vdev));
                IVTV_WARN("Selected firmware errors will be ignored\n");
        } else {
#else
        if (1) {
#endif
                res = ivtv_firmware_check(itv, "ivtv_serialized_open");
                if (res == -EAGAIN)
                        res = ivtv_firmware_check(itv, "ivtv_serialized_open");
                if (res < 0)
                        return -EIO;
        }

        if (s->type == IVTV_DEC_STREAM_TYPE_MPG &&
                test_bit(IVTV_F_S_CLAIMED, &itv->streams[IVTV_DEC_STREAM_TYPE_YUV].s_flags))
                return -EBUSY;

        if (s->type == IVTV_DEC_STREAM_TYPE_YUV &&
                test_bit(IVTV_F_S_CLAIMED, &itv->streams[IVTV_DEC_STREAM_TYPE_MPG].s_flags))
                return -EBUSY;

        if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
                if (read_reg(0x82c) == 0) {
                        IVTV_ERR("Tried to open YUV output device but need to send data to mpeg decoder before it can be used\n");
                        /* return -ENODEV; */
                }
                ivtv_udma_alloc(itv);
        }

        /* Allocate memory */
        item = kzalloc_obj(struct ivtv_open_id);
        if (NULL == item) {
                IVTV_DEBUG_WARN("nomem on v4l2 open\n");
                return -ENOMEM;
        }
        v4l2_fh_init(&item->fh, &s->vdev);
        item->itv = itv;
        item->type = s->type;
        v4l2_fh_add(&item->fh, filp);

        if (item->type == IVTV_ENC_STREAM_TYPE_RAD &&
                        v4l2_fh_is_singular_file(filp)) {
                if (!test_bit(IVTV_F_I_RADIO_USER, &itv->i_flags)) {
                        if (atomic_read(&itv->capturing) > 0) {
                                /* switching to radio while capture is
                                   in progress is not polite */
                                v4l2_fh_del(&item->fh, filp);
                                v4l2_fh_exit(&item->fh);
                                kfree(item);
                                return -EBUSY;
                        }
                }
                /* Mark that the radio is being used. */
                set_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
                /* We have the radio */
                ivtv_mute(itv);
                /* Switch tuner to radio */
                ivtv_call_all(itv, tuner, s_radio);
                /* Select the correct audio input (i.e. radio tuner) */
                ivtv_audio_set_io(itv);
                if (itv->hw_flags & IVTV_HW_SAA711X) {
                        ivtv_call_hw(itv, IVTV_HW_SAA711X, video, s_crystal_freq,
                                SAA7115_FREQ_32_11_MHZ, SAA7115_FREQ_FL_APLL);
                }
                /* Done! Unmute and continue. */
                ivtv_unmute(itv);
        }

        /* YUV or MPG Decoding Mode? */
        if (s->type == IVTV_DEC_STREAM_TYPE_MPG) {
                clear_bit(IVTV_F_I_DEC_YUV, &itv->i_flags);
        } else if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
                set_bit(IVTV_F_I_DEC_YUV, &itv->i_flags);
                /* For yuv, we need to know the dma size before we start */
                itv->dma_data_req_size =
                                1080 * ((itv->yuv_info.v4l2_src_h + 31) & ~31);
                itv->yuv_info.stream_size = 0;
        }
        return 0;
}

int ivtv_v4l2_open(struct file *filp)
{
        struct video_device *vdev = video_devdata(filp);
        int res;

        if (mutex_lock_interruptible(vdev->lock))
                return -ERESTARTSYS;
        res = ivtv_open(filp);
        mutex_unlock(vdev->lock);
        return res;
}

void ivtv_mute(struct ivtv *itv)
{
        if (atomic_read(&itv->capturing))
                ivtv_vapi(itv, CX2341X_ENC_MUTE_AUDIO, 1, 1);
        IVTV_DEBUG_INFO("Mute\n");
}

void ivtv_unmute(struct ivtv *itv)
{
        if (atomic_read(&itv->capturing)) {
                ivtv_msleep_timeout(100, 0);
                ivtv_vapi(itv, CX2341X_ENC_MISC, 1, 12);
                ivtv_vapi(itv, CX2341X_ENC_MUTE_AUDIO, 1, 0);
        }
        IVTV_DEBUG_INFO("Unmute\n");
}